ABSTRACT
Citrobacter species have been reported to cause a wide spectrum of infections in humans and invasive infections are associated with a high mortality rate, with 33 to 48% of patients succumbing to Citrobacter bacteraemia. The high mortality rate associated with Citrobacter infections may be due in part to ineffective empirical antibiotic therapy. Citrobacter has been found to produce SHV and TEM derived Extended spectrum beta lactamases in addition to chromosomal inducible AmpC beta - lactamases which could be contributing to increasing drug resistance. The aims of the study were to detect the prevalence of Citrobacter infections with its associated risk factors, antibiotic susceptibility patterns and determination of beta-lactamase activity- both extended spectrum beta - lactamase and AmpC beta-lactamase activity among Citrobacter isolates. The isolates were identified by standard microbiological procedures. ESBL detection was by double disc diffusion method and AmpC beta-lactamase detection was done using Cefotaxime and Cefoxitin discs. C. braakii (33.3%) was the commonest genomospecies identified followed by C. freundii (21.3%) and C. amalonaticus (16.66 %) among 150 Citrobacter isolates. Diabetes mellitus was the major risk factor. Imipenem (100%)was most effective whereas 98% showed resistance to Ampicillin; carbapenems and fourth generation Cefipime showed better sensitivity than third generation cephalosporins. The study highlights the need for informed antibiotic treatment guided by routine antimicrobial susceptibility and knowledge of the ESBL status of the isolate, the outcome of which undoubtedly will be better patient care.